EP 1449615 A1 20040825 - Numerical control unit for detection of abnormal load on an electric motor
Title (en)
Numerical control unit for detection of abnormal load on an electric motor
Title (de)
NC-Einheit zur Überwachung der Beanspruchung auf einem Elektroantrieb
Title (fr)
Unité de contrôle numérique pour la détection d'une charge anormale sur un moteur électrique
Publication
Application
Priority
JP 2003044200 A 20030221
Abstract (en)
A numerical control unit having a load monitoring function for monitoring a load on a tool drive source during a machining operation. The numerical control unit includes a load monitoring section for monitoring the load on an electric motor; a wear recognizing section for recognizing the current extent of tool wear; a storing section for storing a plurality of preset limit load values corresponding individually to predetermined various extents of tool wear; a calculating section for calculating the current limit load value corresponding to the current extent of tool wear recognized in the wear recognizing section, based on the plurality of preset limit load values stored in the storing section; and a comparing section for comparing the load on the electric motor, monitored in the load monitoring section, to the current limit load value calculated in the calculating section, and for judging on the abnormality of the load. The wear recognizing section recognizes the current extent of tool wear by using one parameter selected from a group consisting of the number of times of use of a tool, the duration of cutting by a tool, the distance of cutting by a tool and the number of times of execution of machining program. The load monitoring section monitors at least one of maximum value, average value and minimum value of the load in a certain procedure of a machining program. <IMAGE>
IPC 1-7
IPC 8 full level
B23Q 17/09 (2006.01); G05B 19/18 (2006.01); G05B 19/4065 (2006.01)
CPC (source: EP US)
B23Q 17/09 (2013.01 - US); B23Q 17/0961 (2013.01 - EP); G05B 19/4065 (2013.01 - EP US); G05B 2219/50328 (2013.01 - EP US)
Citation (search report)
- [A] EP 1166960 A2 20020102 - MURATA MACHINERY LTD [JP]
- [A] US 5857166 A 19990105 - KIM NAM H [US]
- [PA] EP 1342534 A2 20030910 - FANUC LTD [JP]
Designated contracting state (EPC)
DE
DOCDB simple family (publication)
EP 1449615 A1 20040825; EP 1449615 B1 20050706; CN 1243628 C 20060301; CN 1550287 A 20041201; DE 602004000025 D1 20050811; DE 602004000025 T2 20060511; JP 2004252839 A 20040909; JP 3681733 B2 20050810; US 2004174130 A1 20040909; US 6892110 B2 20050510
DOCDB simple family (application)
EP 04003552 A 20040217; CN 200410006853 A 20040220; DE 602004000025 T 20040217; JP 2003044200 A 20030221; US 78088804 A 20040219